Ignore .DS_Store and update git diff command

- Added .DS_Store to .gitignore
- Updated git diff command to use --staged instead of HEAD

.gitignore

@@ -160,3 +160,6 @@ cython_debug/
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 #.idea/
+
+# System
+.DS_Store

src/gencommit.py

@@ -173,7 +173,7 @@ def gencommit():
     commit_description: str
     if commits_exist:
         diff_output: str = subprocess.check_output(
-            ["git", "diff", "HEAD"] + unknown_args, text=True
+            ["git", "diff", "--staged"], text=True
         ).strip()
         formatted_diff: str = format_diff(diff_output)
         commit_message, commit_description = generate_commit_message(